Stone trap for harvester

ABSTRACT

The invention relates to combine harvesters having stone traps for collecting stones and other foreign objects before they reach the threshing means of the harvesters and enabling the trapped stones to be easily removed from the harvesters. A combine harvester according to the present invention comprises a crop elevator having a rear discharge end, threshing means including a rotatable cylinder and a cooperable concave forming a nip therebetween; the nip being spaced rearwardly of the discharge end to define an opening directed downwardly to a stone trap having a lower wall extending downwardly and forwardly to a forward edge; the stone trap having an outlet closable by a door which is pivotally mounted on the forward edge and which, in a closed position thereof, seals against an underside surface of the crop elevator, the crop elevator being capable of adopting an operative position in which the forward edge of the stone trap is disposed beneath the elevator and in which the stone trap extends forwardly of and beneath the discharge end of the elevator.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to combine harvesters having stone trapsfor collecting stones and other foreign objects before they reach thethreshing means of the harvesters and enabling the trapped stones to beeasily removed from the harvesters.

2. Description of the Prior Art

When harvesting windrow crops with a pick-up attachment mounted on aheader of a combine harvester, or when cutting the crops close to theground surface with a direct-cut attachment, stones and other hardforeign objects are frequently picked-up and fed into the harvester. Toavoid damage caused by stones, combine harvesters commonly havetrough-shaped stone traps disposed forwardly of the threshing means.Stones which are fed towards the threshing means are hit by threshingbars of the threshing means and thereby thrown into the trap.

However, small trough-shaped stone traps are not fully adequate forretarding all stones which are likely to cause damage. Larger stonetraps may be fully adequate for retarding the stones, but may alsoadversely influence the fluent transition of crop material from a cropelevator of the harvester to the threshing means. This decreases theefficiency of the harvester.

One attempted solution according to U.S. Pat. No. 3,209,759 has been toprovide a feeder beater above a large stone retarder. However, thisresults in higher cost of the harvester. Moreover, the header, togetherwith the crop elevator, have to be mounted further to the front toaccomodate the feeder beater. This reduces the fore-and-aft stability ofthe harvester.

Another attempted solution according to U.S. Pat. No. 2,652,677 is toprovide a transition plate between the crop elevator and the threshingmeans. The transition plate is held in an operative position relative tothe threshing means by spring biased latches but, in response to apre-determined abnormal pressure, is released and undergoes pivotalmovement. However, the adjustment of traps having such transition plateshas proved very difficult and the operator must be alert to determinewhen the trap opens.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a combine harvesterhaving a fully effective stone trap without the need to provide anyadditional feeder means and yet which does not adversely influence thesmooth flow of crop material from the elevator to the threshing means.

According to the present invention a combine harvester comprises a cropelevator having a rear discharge end, threshing means including arotatable cylinder and a cooperable concave forming a nip therebetween,the nip being spaced rearwardly of the discharge end to define anopening leaning downwardly to a stone trap having a lower wall extendingdownwardly and forwardly to a forward edge, the stone trap having anoutlet closable by a door which is pivotally mounted on the forward edgeand which, in a closed position thereof, seals against an undersidesurface of the crop elevator, the crop elevator being capable ofadopting an operative position in which the forward edge of the stonetrap is disposed beneath the elevator and in which the stone trapextends forwardly of and beneath the discharge end of the elevator.

When the elevator is in the operation position, the discharge end ispreferably spaced substantially vertically below a forward portion ofthe circle generated by the cylinder.

The crop elevator may have a base which extends upwardly and rearwardlywhen the elevator is in the operative position, at the rearward end thebase having an angled portion providing an enlargement in thecross-sectional area of the passage for flow of crop material passingout of the discharge end of the elevator.

A rearward edge of the inlet opening is preferably defined by atransition plate positioned forwardly of the nip, the transition platehaving an upwardly and rearwardly inclined guide surface for guidingcrop material into the nip.

BRIEF DESCRIPTION OF THE DRAWINGS

A combine harvester according to the present invention will now bedescribed in greater detail, by way of example, with reference to theaccompanying drawings, in which:

FIG. 1 is a schematic side view of the combine harvester with a cropelevator in an operative position, parts being cut away to show internaldetail,

FIG. 2 enlarged in scale, is a longitudinal sectional view, on anenlarged scale, of a part of the harvester of FIG. 1,

FIG. 3 is a view similar to that of FIG. 2, but showing the cropelevator in an extreme lowered position,

FIG. 4 is a fragmentary view as seen in the direction of the arrow IV inthe FIG. 3,

FIG. 5 is a view similar to that of FIG. 2, but showing the cropelevator in a raised inoperative position.

FIG. 6 is a view similar to that of FIG. 5, but showing a stone trapdoor of the harvester in an open position, and

FIG. 7 is a view similar to that of FIG. 3, but illustrating an optionalfeature of the combine harvester.

DETAILED DESCRIPTION OF THE INVENTION IN GENERAL

With reference to FIG. 1, the combine harvester comprises a cropelevator 1, the forward end of which supports a header 2. The cropelevator 1 transports cut crop material to threshing means 20 comprisinga rotatable cylinder 3 and a cooperating concave 4, the lattersub-tending an angle of the order of 130° at the rotational axis of thecylinder 3. The combine harvester also comprises a conventional strawbeater 5, straw walkers 6 and a cleaning device 7 for further treatingthe crop material and a grain tank 8 for storage of threshed and cleanedgrain. The operator's platform with a steering column and controls islocated in front of the grain tank 8 and is generally indicated at 9. Astone trap 10 is disposed forwardly of the nip between the concave 4 andthe cylinder 3.

PREFERRED EMBODIMENT

With reference to FIG. 2, the stone trap 10 has side wall portions 11(which are part of the harvester side walls 12), a generally forwardlyand downwardly inclined lower wall 13, a front door 14 and an inletopening 16. A bent plate 15 is secured on the underside of the elevator1.

The wall 13 has a rear, upwardly bent flange 17, a front section 18 anda rear section 19. The front and rear sections 18 and 19 areinterconnected by a step 21. The wall 13 is secured to the side walls 12by mounting brackets 22 which provide front abutment edges 23 for thedoor 14. The shape of the wall 13 provides considerable strength.

The door 14 is hinged at its lower edge to the front edge of the wall 13by hinges 24 and is arranged to abut the edges 23 when in its closedposition in which it closes an outlet of the stone trap 10. When opened(FIG. 6), the door 14 is below the level of the front section 18. Latchplate 25 are pivotally mounted at 26 near the side edges of the door 14and are arranged to hook in recesses 27 (FIG. 3) of brackets 28 (whichare attached to the brackets 22) to hold the door 14 in its closedposition. The door 14 carries a flexible sealing strip 29. A bent edgeportion 30 on the door 14 is intended to give greater strength thereto.

The elevator 1 is pivotally mounted on the framework of the harvester at31 so as to be movable between the positions shown in the drawings. Theelevator 1 has a rear discharge end with a discharge opening 32 facingrearwardly towards the nip between the cylinder 3 and concave 4. A cropconveyor 33 comprising conveyor chains 34 with conveyor slats 35 securedthereto is arranged to move the crop material upwardly over the elevatorbase 36. The elevator base 36 has an angled portion 37 at its dischargeend, the portion 37 providing an enlargement in the cross-sectional areaof the crop material passage to promote smooth flow of crop material.The portion 37 is inclined at a smaller angle to the horizontal than theremainder of the base 36.

The plate 15 is secured to the underside of the base 36 at the dischargeend thereof and, while this plate 15 is not fully arcuate, it isarranged to be generally concentric with the pivot axis 31 of theelevator 1. The sealing strip 29 seals against the plate 15 when thedoor 14 is in the closed position. The sealing strip 29 seals againstthe plate 15 irrespective of the angular position of the elevator 1within its angular range of positions because of the shape of the plate15.

The space between the discharge opening 32 of the elevator 1 and thethreshing concave 4 constitutes the inlet opening 16 of the stone trap10. When the header and the elevator 1 are in the normal operativeposition shown in FIG. 2 (in which the header 2 is spaced closely abovethe ground to receive crop material) the opening 16 is small.

The threshing cylinder 3 comprises flanges 40 and rasp bars 41 mountedthereon. The threshing cylinder 3 is rotated in the direction indicatedby the arrow 42. The outlines 43 and 44 generated by conveyor 33 and thethreshing cylinder 3 closely approach one another, as shown in FIG. 2.

The threshing concave 4 comprises transverse threshing bars 45 mountedin a frame with arcuate side members 46 and a front transverse bar 47.The concave 4 is adjustable in height relative to the threshing cylinder3 for adjusting the clearance nip to suit the crop and the cropcondition. The concave 4 is pivotally supported at its forward end at 48(the rear suspension not being shown). A transition plate 49 having anupwardly and rearwardly slanting guide surface 50 is attached to thefront transverse bar 47 of the concave 4 and is movable therewith. Thetransition plate 49 has a generally vertical front wall 51 which ispositioned adjacent the flange 17 of the floor 13. The front wall 51 ofthe transition plate 49 is shifted generally parallel to the flange 17during adjustment of the concave 4, thereby avoiding any jamming of cropmaterial between the various components.

When the elevator 1 is in the operative position shown in FIGS. 1 and 2,the hinges 24 are disposed beneath the elevator 1 and the stone trapextends forwardly of and beneath the discharge end of the elevator 1.Also, the discharge opening 32 of the elevator 1 is at the samehorizontal level as the nip between the cylinder 3 and concave 4.

OPERATION

In operation, the combine harvester is driven across the field with theelevator 1 and the header 2 mounted thereon in the operative positionshown in FIGS. 1 and 2. Crop material is cut with a direct cutattachment or with a row crop attachment on the header and fed into thecrop elevator 1. The elevator chain 34 with the conveyor slats 35 urgesthe layer of crop material upwardly over the elevator base 36 andtowards the threshing means 20. The layer of crop material is engaged,shortly after leaving the discharge opening 32 of the elevator 1, by therasp bars 41 which deflect the layer in a downward direction and intothe nip between the threshing cylinder 3 and the threshing concave 4.The glide surface 50 assists in guiding the crop layer into the nip. Theangled portion 37 of the elevator base 36 assists in providing a smoothtransition from the elevator 1 to the threshing means 20. The risk ofcrop plugging in this area is therefore reduced to a minimum. Thethreshing means 20 and other crop treating means in the harvesteroperate under a generally constant load and at high efficiency becauseof the smooth flow of the crop layer.

The stone trap 10 will be filled up with chaff, short straw and grainsoon after starting operation. This further enhances smooth flow of thecrop layer over the stone trap. The material in the stone trap forms asoft mass for receiving stones and other hard foreign objects. Indeed,all stones and other hard foreign objects fed to the threshing means 20are hit by the rasp bars 41 which revolve at high speed, whereby thestones or other hard objects are thrown towards and into the soft massin the stone trap 10. With the stone trap 10 extending underneath thedischarge end of the elevator 1, it thus has become possible to providea large and hence very efficient stone trap for the reasons explainedabove, and yet to maintain a continuous and smooth flow of crop materialfrom the elevator 1 to the threshing means 20. The design of thecomponents of the harvester enables the header 2 and elevator 1 to beraised to inoperative transport position (FIGS. 5 and 6) without anysqueezing of material in the stone trap 10 and without any aperturebeing formed between the elevator base 36 and the strip 29.

Adjustment of the concave 4 is easily possible without any squeezing orjamming of crop material between the various components as the wall 51is arranged to move generally parallel to the flange 17.

The stone trap 10 can easily be emptied and cleaned from below theelevator 1 by unlatching and opening the door 14 to the open positionshown in FIG. 6. The door 14 also provides access to the transition areabetween the elevator 1 and the threshing means 20 for cleaning anyplugging which might nevertheless occur.

The combine harvester shown in the drawings thus has a large stone trapwithout the necessity of an additional feeder beater, as has been commonpractice in the past. It will also be appreciated that the discharge endof the elevator base 36 together with the bent plate 15 form a strongstructure which can resist normal forces acting thereon duringoperation.

For those situations where stones or other hard foreign objects are notlikely to be encountered, e.g. because the crop (such as maize) is cutfrom the stubble at a substantial height above the ground, a fillerplate 60 may be fitted in the stone trap 10, as shown in FIG. 7.

Having thus described the invention, what is claimed is:
 1. A combineharvester comprising:a chassis; a crop elevator mounted on the chassisand pivotable between a raised inoperative position and a loweredoperative position and having a bottom wall with a rear discharge edge;threshing means mounted on the chassis and having a rotatable threshingcylinder and a cooperable threshing concave forming an intake niptherebetween and at the forward end of the concave, the nip being spacedrearwardly of the bottom wall discharge edge to define therebetween anopening leading downwardly; a stone trap supported on the chassis withinthe downwardly leading opening and having a lower wall extendingdownwardly and forwardly to a forward edge, the fore-and-aft dimensionof the stone trap exceeding substantially the fore-and-aft dimension ofthe downwardly leading opening when the elevator is in the operativeposition and the stone trap having an outlet at the forward edge; a doorpivotally mounted on the forward edge for closing the stone trap, thedoor sealing against, the bottom wall when in a closed position, theforward edge of the stone trap being disposed beneath the elevator whenthe latter is in the operative position and the stone trap extendingforwardly of and beneath the discharge edge of the elevator.
 2. Thecombine harvester as recited in claim 1, wherein when the elevator is inthe operative position, the discharge edge is spaced substantiallyvertically below a forward portion of the circle generated by thecylinder.
 3. The combine harvester as recited in claim 1, wherein whenthe elevator is in the operative position, the discharge edge isprovided substantially at the same level as the intake nip between thethreshing cylinder and cooperable concave.
 4. The combine harvester asrecited in claim 1, wherein the elevator bottom wall extends upwardlyand rearwardly when the elevator is in the operative position, andwherein the bottom wall comprises an angled portion providing anenlargement in the cross-sectional area of the passage for flow of cropmaterial passing out of the discharge edge of the elevator.
 5. Thecombine harvester as recited in claim 1, further comprising a transitionplate supported on the chassis positioned forwardly of the intake nip,the transition plate defining a rearward edge of the opening and havingan upwardly and rearwardly inclined guide surface for guiding cropmaterial into the intake nip.
 6. The combine harvester as recited inclaim 5 wherein the transition plate is attached to the forward end ofthe concave for adjustment together therewith relative to the threshingcylinder.
 7. The combine harvester as recited in claim 1 wherein thestone trap door comprises a flexible sealing strip for engaging theunderside surface of the elevator throughout the range of pivotalmovement of the elevator.
 8. The combine harvester as recited in claim 7wherein the underside surface of the elevator comprises a shaped platefor the sealing strip to seal against, the shaped plate being arrangedsuch that it generally extends partially around the pivotal centre ofmovement of the elevator for effective sealing of the sealing stripagainst the shaped plate throughout the range of pivotal movement of theelevator.
 9. A combine harvester comprising:a rotatable threshingcylinder generating a circle; a threshing concave mounted adjacent thethreshing cylinder and cooperable therewith for threshing crop material,the threshing cooperable therewith for threshing crop material, thethreshing cylinder and threshing concave forming an intake niptherebetween at the forward end of the threshing concave; the intake nipbeing positioned rearwardly of a forward portion of the circle generatedby the threshing cylinder; a crop elevator forwardly of the threshingcylinder and threshing concave and capable of adopting an operativeposition in which the forward end of the elevator is lowered; the cropelevator having a bottom wall, and being operable to feed crop materialupwardly over the bottom wall towards the intake nip, the bottom wallhaving a rear discharge edge which, when the elevator is in theoperative position is spaced substantially vertically below a forwardportion of the circle generated by the threshing cylinder andsubstantially horizontally forwardly of the intake nip, and stone trapmeans having a generally horizontally extending inlet between thedischarge edge of the elevator bottom wall and the intake nip, andextending in a forward and downward direction substantially below andforwardly of the discharge edge of the elevator bottom wall, when theelevator is in the operative position, the fore-and-aft dimension of thestone trap exceeding substantially the width of the spacing between thebottom wall discharge edge and the intake nip.
 10. The combine harvesteras recited in claim 9, wherein the crop elevator is pivotally movablebetween an operative position in which the forward end of the elevatoris lowered, and an inoperative position in which the forward end of theelevator is raised, and wherein the stone trap means further comprise:alower wall extending forwardly to a forward edge, and a door pivotallymounted on the forward edge for closing the stone trap means, the doorsealing against an underside surface of the elevator bottom wallthroughout the range of pivotal movement of the elevator, when in aclosed position.
 11. The combine harvester as recited in claim 10,wherein the underside surface of the elevator bottom wall comprisesfirst sealing means generally extending partially around the pivotalcentre of movement of the elevator and wherein the door comprisesfurther flexible sealing means engaging the first sealing meansthroughout the range of pivotal movement of the elevator for effectivesealing therewith, when the door is in the closed position.